26 August, 2022

QDX on 17 and 15 m: Receiver

I got myself one of the marvellous digital transceivers from QRPLabs recently: The QDX - QRPLabs Digital Transceiver. It is set up with receiver bandpass filters and transmitter lowpass filters for 80, 40, 30, and 20 m. It has also been found that the 40 m filters work well for 60 m. 

The latest firmware, version 1_04, has a new "Band Configuration" screen where one may configure the list of supported bands. It is the intention that higher bands will eventually be supported.

I am not so interested in 80 m, so I wanted to see if I already now could get the receiver to work on 17 m and 15 m. With reference to the schematics, I modified the input filter's inductor, L12. 

07 August, 2022

French, Spanish, German, Icelandic, Swedish, ...

The multi-face Arduino GPS clock is inspired by the Clock Kit from QRPLabs. It is an open source project on GitHub, and it now has support for many more languages in the newly released versjon 1.4.0. As a language nerd myself, I love fiddling with multiple languages and character sets.

The local language option is for display of day name in case local time is shown. The default is English for local time. No matter the choice for local time, English is always used for UTC day name. Here are examples:

French:


Spanish:

23 June, 2022

Reversing the inductor in the Chinese QRP antenna tuner makes all the difference

Like many I was disappointed with the Chinese antenna tuner kit "QRP manual days" back in 2014 and I never really got it to work. 

That was even after I had replaced the two polyvaricon capacitors. The two screws for mounting each of the variable capacitors were too long. The result was that they interfered with the moving plates of the capacitor and I ruined both of them. There was no warning of this in the manual, so beware anyone who buys this kit.

Despite fixing this, it didn't really tune anything. I later learned that it probably works for low bands like 80 m as it is, but I didn't notice that. I thought maybe the toroid core of the inductor was of inferior quality, but never really investigated it, so it sat unused on the shelf for 7-8 years.

14 June, 2022

SV8/LA3ZA part 2

Below is a map showing contacts made from Pythagorio, Samos, early June 2022 using FT8. I tried to contact as many entities (~countries) as possible and got to a total of 55. The main band was 30 m, secondarily 20 m. 40 m and 17 m were also used. 

My quarter-wave antenna @ 30m, shown to the left in the image, performed well, despite the high noise level from the adjacent high-voltage line. The image is in the direction of Turkey (South-East), which is not visible at the time of the image.

03 June, 2022

SV8/LA3ZA

The polymath Pythagoras was born on
Samos and his birthplace village is now
called Pythagorio.
For a short while I’m operating from Samos, Greece with my old K2 at 10 W output. Noise level here next to a high voltage line is S9+ on all bands except 6m, so only digital modes work. The K2's noise blanker does a good job of removing some of the noise.

The antenna is a quarter-wave vertical for 30 m which also tunes several other bands. It’s on the balcony with a 7 m Sotabeam glass fiber mast, on the left-hand side of the street in the image below.

05 April, 2022

Even more functions for the Arduino GPS Clock

The multi-face Arduino GPS Clock has some new clock faces in software version 1.3.0:

  • Demo mode, where all screens are cycled through, with 10-15 seconds per screen
  • Astronomical clock
  • Wordclock display
  • Roman numbers
  • Morse code clock
This brings the total to 35 different screens. The updated code as well as documentation is on my Github page.

08 March, 2022

Ham meeting 2022

The Norwegian Ham meeting 2022 will take place 11-13 March near Oslo Airport Gardermoen. Norwegian and some Swedish radio amateurs will meet and the program is here (Norwegian). It will be nice finally to meet again!

I will give a presentation on Saturday morning: "An easy-to-build GPS clock for the shack".